"I think the hardest part for me, I struggle with her feeling so isolated at home. That's my biggest concern. I want to make sure she feels connected," her husband said.

Research shows that lifestyle choices can reduce the rate of cognitive decline. And so Casey exercises daily, taking walks or doing yoga. She exercises her brain as well: playing online word games and coloring.

"It's not going to help me to be depressed, because if you're depressed your brain doesn't work well," Casey said.

Instead of swelling on all the memories in their photo book, they are scrambling to make new ones. They just returned from a trip to Scotland and Ireland, and are traveling to Italy this summer.

"Live your life now. You never know what's going to happen," Casey said.

Tina's case of Alzheimer's is considered mild. Because she's so young, there's not a lot of research or clinical trials for patients her age. Rosenbloom hopes hearing stories like Casey's might change that.